One of the problems of transporting liquids in disposable cups, such as coffee cups, where it is the intention that the coffee be consumed away from the premises is the need for an effective lid or cap for the liquid container. A typical example is the well known styro-foam cup and its mating snap-on formed plastic lid. At the time the user desires to consume the liquid, he must carefully remove the snap-on cap or lid for drinking the contents. If the contents happened to be hot coffee and the user is in a moving vehicle such as an automobile, or inattentive, the end result is usually spillage, and a possible accident.
Some people have taken to leaving the lid in place and punching a hole in the lid, using whatever sharp instrument is available, and then attempting to drink the fluid through the punched out hole.
Some lids are pre-punched with openings designed to receive a straw. Such holes, however, are usually centered and require the use of a straw for any significant amount of fluid to be withdrawn from the container into the user's mouth. This arrangement is useless for the coffee drinker.
Although disposable drinking cups are usually made of styro-foam or paper which is easily perforated, the lids are usually made of polystyrene, polyethylene, or polypropylene. These are relatively tough materials and not easily perforated outside of the factory. Thus perforation by the user or the vendor using the pointed instrument such as a knife, can be dangerous.